The pavement milling machine is one of the main machines of pavement maintenance construction machinery, and it is a most economical modem maintenance method for milling damaged old paving layers by using the pavement milling machine, and laying new surface layers. Due to its advantages such as its high working efficiency, simple construction process, easily controllable milling depth, convenient and flexible operation, good maneuvering performance, and directly recycled and utilized milled old materials, the method is widely applied to urban municipal roads and highway maintenance projects.
When the milling machine needs to be as close as possible to an obstacle, for example, when milling a road edge, it is necessary to place the support leg on one side into the inner side of the milling machine, so that a milling drum can be as close as possible to the milling plane of the road edge, and smoothly complete the milling work of the road edge. In addition, in order to ensure stably steering of a vehicle when the support leg is placed inside, a track under the support leg also needs to be steered accordingly.
At present, the existing support leg swing is achieved by rotating around a pin roll fixed on the milling machine frame by a certain angle, however, at this time a tire or the track is also rotated by the corresponding angle following the swing of the support leg, so an additional reversing valve needs to be installed to switch oil inlet and outlet lines to change the direction of the tire or the track, which increases the cost. An alternative method for ensuring that the advancing direction of the tire or the track is unchanged before and after swinging through a four-bar mechanism, but its defect is that the tire or the track cannot be steered and an additional device is required to control the steering.